(1) The hot spot is at the top of the container, and the hot spot solidifies at last and the feeding is blocked by the surrounding, so the feeding condition is poor, and there is a great tendency to produce shrinkage defects. In order to reduce the adverse effects of the hot spot and ensure the performance of the ductile iron spent fuel container, different casting processes are adopted at the hot spot and the simulation analysis is carried out, and it is found that the ductile iron spent fuel container is not suitable The influence of the same casting process on the hot spot is different: the heat dissipation condition of sand mold chill is poor, the solidification time is as long as 8.5H, and the solidification speed difference between the top hot spot and the vessel body is large, which can not eliminate the adverse effect of the hot spot; using the full chill casting process, not only the cooling condition of the top hot spot of nodular iron spent fuel container is greatly improved, but also the solidification speed is low It is very important to ensure the consistency of microstructure and properties of ductile iron spent fuel container;
(2) When the thickness of full chill and metal mold at the top hot spot increases to 450mm, the solidification time of the spent fuel container with ductile iron core is the shortest, which is 3.5H; increasing the thickness of full chill can not shorten the solidification time of the spent fuel container with ductile iron core; considering comprehensively, 450mm metal mold + 450mm full chill is used at the top hot spot The results show that the solidification time of spent fuel container is 3.5 h;
(3) The results of casting process simulation, temperature measurement and dissection of 45 ° sector test block of 100 ton ductile iron spent fuel container have been applied to the optimization and scheme design of 1:1 100 ton ductile iron spent fuel container casting with good effect.